The present invention relates to electrical shielding, specifically, physical barriers for the prevention of tactile interface with leads on terminal boards which are drawing current, often called xe2x80x9chotxe2x80x9d leads, and will be described with particular reference thereto. It is to be appreciated that the present invention is also applicable to various other uses and is not limited to the aforementioned application.
Electrical terminal boards are used as hubs for a plurality of wire junctions. Current flow through such terminal boards can reach dangerous levels, such that contact with open leads of the terminal boards can cause injury or even death. In an effort to circumvent such incidences, an Underwriters Label (UL) requirement mandates that such xe2x80x9chotxe2x80x9d leads be covered with an insulator to prevent electrical shock. Currently, in accordance with UL Code 56 applied aptly dubbed the xe2x80x9cfickle fingerxe2x80x9d test, a finger shaped probe is used to prod a covered terminal board or other electrical device. If the probe successfully touches any hot leads, then the device fails the test.
Presently, large covers may be provided to encompass a plurality of terminal boards located in the same vicinity. If a technician wishes to access a single terminal board, he removes the cover exposing all of the terminal boards. Typically, power to all of the terminal boards under the cover is cut for the safety of the technician, even though the technician only needs to access one terminal board. This means that working systems could be down while completely unassociated systems are being repaired or maintained. In order for such a barrier to be practical, a relatively large number of terminal boards are contained within the cover, which means a large number of non-associated systems are down while one terminal board is being accessed.
Another method of guarding terminal boards is to supply cardboard covers roughly shaped to bar access to hot leads. Cardboard barriers are easily misshapen, and do not withstand humid environs well. Further, additional means of attachment are used to secure the cardboard about the terminal board.
Either of the aforementioned methods requires the removal of the cover to access the terminal board.
Fuse blocks present similar problems to those discussed above in that they have exposed leads when in operation. Additionally, a UL specification requires that in a dual fuse system, both fuses are to be removed simultaneously. With typical fuse pullers, it is possible to rotate the puller only freeing one fuse, leaving the second fuse in the circuit.
The present invention provides a new and improved method and apparatus which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, a barrier for limiting accessibility to electrically conductive boards is provided. The barrier includes a plurality of board-engaging sides having proximal and distal edges to the board. A cover side is formed between the distal edges. Securements secure the barrier to the board.
In accordance with another aspect of the present invention, a method of preventing access to an electrically conductive board is provided. A barrier is attached to a board that prevents tactile access to the board. The barrier includes board-engaging sides, a cover side and securements to hold it in place on the board.